This relates generally to a wheelchair assembly which is power driven and steered, although may be manually steered, and in which the seat may be raised and lowered, rotated and universally tilted. More particularly, the seat may be rotated and the wheels steered together or independently, and the wheels may be automatically aligned with the direction chosen for wheelchair travel.
Known motor assisted wheelchairs normally comprise a standard wheelchair capable of being power driven and steered. Such a power wheelchair typically has its occupant seat mounted on a pair of rather large rear wheels and a pair of front casters, the rear wheels capable of being power driven together or independently of one another to effect steering. If the same basic wheelchair frame is retained, the added weight and frame stress caused by the batteries and motor controlling mechanisms may result in considerable maintenance and repair costs and the attendant downtime needed to insure the safety and reliability of the wheelchair. Moreover, these power operated wheelchairs are heavy and cumbersome and cannot therefore be readily loaded into and unloaded from a motor vehicle, for example, for transport. The versatility during use of these wheelchairs is also lacking in that the seat occupant must always face in the same direction as the direction of travel thereby preventing the occupant to shift slightly to the left or to the right while facing forwarding as, for example, when seated at a dining table or when otherwise seated indoors. And, the fixed elevation of the seat above the ground, normally higher than a typical indoor seat, is not only distracting for the wheelchair-confined invalid when in the company of others not confined to a wheelchair, but is also inconvenient because the wheelchair occupant is unable to sit within a normal distance from a dining room table, for example, because of the seat height constraint.
Another drawback noted during operation of the presently available powdered wheelchairs concerns the safety harzard presented while moving along an incline or a decline such as a long walkway ramp. The weight of the occupant shifts the wheelchair center of gravity possibly causing the wheelchair-confined invalid to topple if left unattended. And, when particularly moving along an incline, the vision of the wheelchair occupant is blocked to some extent by being tilted rearwardly thereby creating a safety hazard especially if left unattended.